# Thermal Energy and Specific Heat Problems ```Thermal Energy and Specific Heat Problems
Formulas/Conversions
1 Calorie = 4.185 J
Celsius to Fahrenheit Conversion
&deg;F = (9/5 &deg;C) + 32
Fahrenheit to Celsius Conversion
&deg;C = 5/9 (&deg;F -32)
Celsius to Kelvin Conversion
K = &deg;C + 273
Q = (m) (ΔT)(C)
C = (Q) / (m ΔT)
Thermal Energy and Specific Heat Problems
1. A 15.75-g piece of iron absorbs 1086.75 joules of heat energy, and its temperature
changes from 25&deg;C to 175&deg;C. Calculate the specific heat capacity of iron in J/g&deg;C.
2. How many joules of heat are needed to raise the temperature of 10.0 g of aluminum
from 22&deg;C to 55&deg;C, if the specific heat of aluminum is 0.90 J/g&deg;C?
3. To what temperature will a 50.0 g piece of glass raise if it absorbs 5275 joules of heat
and its specific heat capacity is 0.50 J/g&deg;C? The initial temperature of the glass is 20.0&deg;C.
4. Calculate the specific heat capacity of a piece of wood if 1500.0 g of the wood absorbs
6.75&times;104 joules of heat, and its temperature changes from 32&deg;C to 57&deg;C.
5. 25.0 g of mercury is heated from 25&deg;C to 155&deg;C, and absorbs 455 joules of heat in the
process. Calculate the specific heat capacity of mercury in J/g&deg;C.
6. What is the specific heat capacity of silver metal if 55.00 g of the metal absorbs 47.3
calories of heat and the temperature rises 15.0&deg;C?
7. Octane, a substance found in petroleum, boils at 126&deg;C and is a liquid over a range of
183 Celsius degrees. What is the melting point of octane in kelvins?
Thermal Energy and Specific Heat Problems
8. A 120g sample of an unknown substance was heated from 15oC to 30oC. The
substance absorbed 458 joules of energy. What is the specific heat of this substance?
9. A 2.0-kg slab of concrete requires 11 kJ to raise its temperature from 23&deg;C to 29&deg;C.
What is the specific heat of concrete in J/g&deg;C?
10. If the temperature of 28 g of ethanol increases from 15oC to 65.5 oC, how much heat
was absorbed by the ethanol? (Specific heat ethanol = 2.44 J/goC)
Convert the following temperatures to both &deg;F and Kelvin
11. -257.87 &deg;C
&deg;F
K
12. -40.0 &deg;C
&deg;F
K
13. 1064&deg;C
&deg;F
K
14. How much energy is needed to increase the temperature of 755 g of iron from 283 K
to 403 K (CIron = 0.46 J/g&deg;C)?
15. If the specific heat of water is 4.185 J/g&deg;C , how much energy must a refrigerator
absorb from 225 g of water to freeze the water if the initial temperature is 35 &deg;C?
16. What mass of water is required to absorb 4.7 x 105 J of energy from a car engine when
the temperature increases 57 &deg;C?
17. A vanadium bolt gives up 1124 J of energy as its temperature drops 25 K. If the bolt’s
mass is 0.093 kg, what is the specific heat J/g&deg;C?
18. Determine the change in energy if 550 g of copper (C = 0.39 J/g&deg;C) is heated from 318
K to 24 &deg;C.
19. The temperature of deep space is thought to be around 3 K. What is this temperature
in &deg;F?
Thermal Energy and Specific Heat Problems
20. Determine the amount of energy needed to raise the temperature of a silver necklace
(specific heat = 0.23 J/g&deg;C) with a mass of 22.5 g from 77 &deg;F to 37 &deg;C.
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